1. Field of the Invention
The present invention relates to a semiconductor apparatus and an output transistor of a horizontal register for a solid-state image pickup apparatus provided with a protection circuit connected thereto.
2. Description of the Related Art
A MOS transistor incorporated in a circuit is sometimes used with the gate of the MOS transistor directly connected to a grounding terminal. For example, the gate of the output transistor of the horizontal register for a solid-state image pickup apparatus is usually connected to the grounding terminal.
In the output transistor of the described arrangement, it is possible that the gate insulating film of the output transistor is broken when an electrostatic impulse is impressed on the grounding terminal.
For example, when an electrostatic impulse is impressed on the input terminal 112 of the horizontal register 111 shown in FIG. 12, the insulating film 115 between the output gate 113 and the gate 114 or the insulating film 116 over the gate 114, etc., is liable to break down.